FACT SHEET Tropical

Summary On Monday 17 April 2006 Monica formed in the off the coast 710km east of Lockhart River (see Figure 1). The Bureau of Meteorology monitored the cyclone as it passed through Queensland territory (see Appendix 1). • Category 3 cyclone in Queensland, with minimum recorded central pressure of 960hPa. • Large significant wave heights recorded in the (see Table 1 and Figure 3). • 0.74m recorded at . • Reports of only minor erosion damage to beaches. • Significant local flooding in area.

Figure 2 – Track of tropical cyclone Monica Tide recording The EPA operates a storm tide system (comprising 22 tide gauges along the Queensland coastline). This allows real-time access to tide data via the public telephone network during events to monitor the effects of from tidal surge.

For this event, tide data was obtained from the Mossman River, Cooktown, Weipa and Karumba gauges (see Figure 2). Figure 2 also shows the similarity in the tracks of tropical cyclone Monica and tropical , which crossed over Cape York in March 2005. Figure 1 – TC Monica, 20 April 2006 (courtesy of BoM, copyright Commonwealth of reproduced with permission) Plots of the records from the tide sites are shown in Wave recording Figures 6–9. Table 3 shows a list of the maximum surge The EPA operates a network of wave monitoring stations values recorded at each of the above storm tide gauges. along the Queensland coastline. Sites at Cairns and Table 3 – Recorded surge heights Weipa were monitored during this event (Figure 2). Surge Exceeded Site Date & time Peak wave conditions recorded at these stations are (m) HAT shown Table 1. Mossman 20/04/2006 09:10 1.23 No Table 1 – Recorded significant wave heights* Cooktown 18/04/2006 23:20 0.49 No Site Date & time Hsig(m) Rank Weipa 20/04/2006 02:30 0.74 No Cairns 19/04/2006 22:30 1.53 10 Karumba 17/04/2006 07:40 0.69 No Weipa 20/04/2006 04:00 2.06 36 ∗ See glossary Flooding While this event did not produce a significant storm surge Table 2 shows the maximum individual wave heights it did result in widespread rainfall over much of Cape (Hmax) recorded at these stations during the event. York (as suggested by the large cloud mass visible in the Table 2 – Maximum recorded individual wave heights* satellite image in Figure 1). This led to considerable river Site Date & time Hmax(m) Rank flooding across a wide area of northern Queensland. An Cairns 19/04/2006 23:30 2.85 14 example of this flooding is clearly displayed in the plot Weipa 20/04/2006 05:00 4.24 17 from the Mossman River (see Figure 6). ∗ See glossary Plots of wave heights and periods from Cairns and Weipa EPA Web Sites wave recording stations are shown in Figures 4 and 5. During the event, the following EPA wave and tide web The peak maximum individual wave height (4.25m Hmax sites were updated at regular intervals: at Weipa) during this event is the 17th largest recorded www.epa.qld.gov.au/waves by the EPA at this site since recordings commenced www.epa.qld.gov.au/tides there in December 1978.

FS 2006-4 Updated 18/05/2006

Glossary Hsig The significant wave height (in metres), defined as the average of the highest one third of the zero up-crossing wave heights in a 26.6-minute wave record. This wave height closely approximates the value a person would observe by . Significant wave heights are the values reported by the Bureau of Meteorology in their forecasts. Hmax The maximum zero up-crossing wave height (in metres) in a 26.6-minute record. Tz The average of the zero up-crossing wave periods (in seconds) in a wave record. Tp Wave period at the peak spectral energy (in seconds). This is an indication of the wave period of those waves that are producing the most energy in a wave record. Depending on the value of Tp, waves could either be caused by local wind fields (sea) or have come from distant storms and have moved away from their source of generation (swell). Figure 4 - Cairns wave data 17–20 April 2006

Direction The direction that peak wave period (Tp) waves are coming from (in ° Magnetic). In other words, where the waves with the most wave energy in a wave record are coming from.

Figure 5 - Weipa wave data 17–20 April 2006

Figure 3 – Tropical cyclone Monica wind vectors 20 April 2006, from NASA/JPL's SeaWinds Scatterometer on QuikSCAT satellite (courtesy of NOAA/NESDIS/Office of Research and Applications, reproduced with permission)

Figure 6 –Tides at Mossman River 17–20 April 2006 Figure 9 –Tides at Karumba 17–20 April 2006

Figure 7 –Tides at Cooktown 17–20 April 2006

Figure 8 –Tides at Weipa 17–20 April 2006

Advice Date (EST) Latitude Longitude Category Central pressure 1 17/04/2006 10:00 -12.4000 150.0000 1 - 2 17/04/2006 16:00 -12.5000 149.6000 1 - 3 17/04/2006 22:00 -12.6000 149.4000 1 - 4 18/04/2006 04:00 -12.6000 148.5000 2 985 5 18/04/2006 07:00 -12.8000 148.4000 2 985 6 18/04/2006 10:00 -12.9000 147.8000 2 980 7 18/04/2006 13:00 -13.1000 147.2000 2 980 8 18/04/2006 16:00 -13.3000 146.6000 2 980 9 18/04/2006 19:00 -13.5000 146.0000 2 975 10 19/04/2006 22:00 -13.0000 145.6000 3 970 11 19/04/2006 01:00 -13.0000 145.1000 3 965 12 19/04/2006 04:00 -12.9000 144.8000 3 965 13 19/04/2006 05:00 -12.5000 144.8000 3 965 14 19/04/2006 07:00 -12.6000 144.6000 3 960 15 19/04/2006 08:30 -12.7000 144.5000 3 960 16 19/04/2006 09:30 -12.7000 144.4000 3 960 17 19/04/2006 10:30 -12.9000 144.3000 3 960 18 19/04/2006 11:30 -13.0000 144.0000 3 960 19 19/04/2006 12:30 -13.0000 143.8000 3 960 20 19/04/2006 13:30 -13.0000 143.7000 3 960 21 19/04/2006 14:00 -13.0000 143.5000 3 960 22 19/04/2006 15:00 -13.1000 143.4000 3 960 23 19/04/2006 16:00 -13.1000 143.4000 3 960 24 19/04/2006 17:00 -13.2000 143.3000 3 965 25 19/04/2006 19:00 -13.3000 143.1000 3 965 26 19/04/2006 22:00 -13.6000 142.6000 3 965 27 20/04/2006 02:00 -13.7000 142.1000 2 975 28 20/04/2006 04:00 -13.7000 142.0000 2 980 29 20/04/2006 07:00 -13.7000 141.8000 2 980 30 20/04/2006 10:00 -13.6000 141.5000 2 985 31 20/04/2006 13:00 -14.1000 141.1000 2 985 32 20/04/2006 16:00 -14.0000 140.6000 2 980 33 20/04/2006 19:00 -13.7000 140.5000 2 975 34 20/04/2006 22:00 -13.8000 140.4000 2 980 35 21/04/2006 01:00 -13.7000 140.2000 3 970 36 21/04/2006 04:00 -13.6000 140.2000 3 960 37 21/04/2006 07:30 -13.6000 140.0000 3 960 Appendix 1 – Tropical cyclone Monica details 17–21 April 2006